• Journal of the Korean Institute of Telematics and Electronics C
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• v.36C no.7
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• pp.17-26
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• 1999

In this paper, Bit selectable and Bi-directional Interface Device is described, which can communicate data with the peripheral devices. Specially, an algorithm of truth-table comparison that synthesizes the pulse-type sequential circuit pulse has been proposed to design the Interrupt Generator, and implemented in designing the Interrupt Register. Also, a description of the asynchronous design method is given to remove the clock skew phenomenon, and the output asynchronous control method which finds the optimal clock and controls all the enable signal of the output pins at the same time is presented. Using this technique interface ports have delay time of less-than 0.7ns.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.8 no.1
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• pp.18-28
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• 1998

A laboratory experiment was made of a control of temperature oscillation in Czochralski convection. Numerical computation was also made to delineate the control of temperature oscillation. The suppression of temperature oscillation was achieved by varying the rotation rate of crystal rod ($\Omega=\Omega_0(1+A sin 2{\pi}ft/t_p)$), where A denotes the amplitude of rotation rate and f the frequency factor. Based on the inherent dimesionless time period of temperature oscillation ($t_p$), the suppression rate of temperature oscillation was characterized by the mixed convection parameter ($0.217{\leq}Ra/PrRe^2{\leq}1.658$). The optimal values of A and f were also scrutinized. To understand the suppression mechanism of temperature oscillation, the controls of isotherm($\theta$) and equi-vorticity($\omega$) were investigated.

• Transactions of the Korean Society of Mechanical Engineers
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• v.11 no.6
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• pp.923-934
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• 1987

A flexible one-link robotic manipulator is modelled as a rotating cantilever beam with a hub and tip mass. An active control law is developed with consideration of the distributed flexibility of the arm. Equation of motion is derived by Hamilton's principle and, for modal control, represented as state variable form using Galerkin's mode summation method. Feedback coefficients are chosen to minimize the linear quadratic performance index(PI). To reconstruct the complete state vector from the measurements, an observer is proposed. In order to suppress vibration of the manipulator arm to desirable extent and to obtain accuracy of the positioning, weighting factor of input in PI is adjusted. Spillover effect due to the controller which controls several important modes is examined. Experiment is also performed to validate the theoretical analysis.

• Journal of Advanced Marine Engineering and Technology
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• v.27 no.1
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• pp.57-64
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• 2003

The characteristics of fuel spray have an important effect on engine performance such as power, specific fuel consumption and emission because fuel spray controls the mixing and combustion process in an engine. Therefore, if the characteristics of fuel spray can be measured, they can be effectively used for improving engine performance. The major factors controlling fuel spray are injection pressure, ambient pressure and engine speed. In this study, the experiment is performed in a high temperature and high pressure chamber. In experiments, spray tip penetration, spray angle and spray tip velocity are measured at various injection pressure (10 and 14 MPa), ambient pressure(3,4 and 5 MPa), fuel pump speed(500, 700 and 900 rpm). Experimental results are useful for deriving an experimental spray equation and design an optimal engine. The results showed that injection pressure, ambient pressure and fuel pump speed are important factors influencing on the characteristics of spray. 1) Injection pressure influences on the characteristics of spray. That is, as injection pressure is increased, spray angle is decreased but spray penetration and spray tip velocity is increased. 2) Spray angle and spray penetration are increased as fuel pump speed is increased.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.04a
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• pp.373-376
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• 1996

The design development, and production of a product is one of the greatest challenges which flexible manufacturing systems face today. No matter how a company refines and controls the manufacturing process, if the product is not properly designed, it will not operate correctly or performed well. Therefore the focus on quality of design must be balanced. One such strategy certain to address the managerial and manufacturing of the future is concurrent engineering. Concurrent engineering calls for the consideration and inclusion of product design attributes satisfying all the design constraints such as customer requirements. Furthermore, concurrent engineering has been recently promoted in many industries as a response to competitive marketing pressures. Viewed as a systematic approach of creating high quality products and bringing them to market at lower cost and in significantly less time, it also attracts the attention of quality designers. In this paperm a methodology and model for optimizing the product design, especially selection of optimal design alternative, is developed. The focus of this paper is on product design as the most critical activity of concurrent engineering. The model is based on the customer requirements for quality. Customer requirements for a certain product can be grouped based on the various design attributes. The design attributes have the priorities. The number of design functions. Design attributes value are calculated, however these values are applied to the optimization method. Numerical example will be illustrated.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.6
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• pp.2753-2758
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• 2012

Rubia cordifolia Linn, which belongs to the Rubiaceae family, is a well-known herb used in Ayurvedic medicine. In the present study, we investigated the influence of a methanolic extract (RC) on the induction of apoptosis in HEp-2 (human laryngeal carcinoma) cell line, as evidenced by cytotoxicity, morphological changes and modification in the levels of pro-oxidants. Inhibition of cell proliferation and lactate dehydrogenase (LDH) release increased in a time and dose-dependent manner. Further, reduced glutathione (GSH), glutathione transferase (GST) and protein levels decreased and lipid peroxidation increased significantly on RC treatment in a dose dependent manner when compared to controls. Based on the results we determined the optimal dose as 30mg/ ml and the apoptotic effect of RC extract (30 mg/ml) on HEp-2 cells was confirmed by fluorescent microscopy and transmission electron microscopy (TEM) based on morphological and ultrastructural changes. RC extract suppressed the proliferation of HEp-2 oral cancer cells inducing apoptotic cell death in vitro. These results point to potential of RC extract as an agent for the treatment of laryngeal squamous cell carcinoma.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.8
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• pp.627-635
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• 2012

This study aims at developing an artificial neural network(ANN)-based predictive and adaptive temperature control method to control the openings at internal and external skins, and heating systems used in a building with double skin envelope. Based on the predicted indoor temperature, the control logic determined opening conditions of air inlets and outlets, and the operation of the heating systems. The optimization process of the initial ANN model was conducted to determine the optimal structure and learning methods followed by the performance tests by the comparison with the actual data measured from the existing double skin envelope. The analysis proved the prediction accuracy and the adaptability of the ANN model in terms of Root Mean Square and Mean Square Errors. The analysis results implied that the proposed ANN-based temperature control logic had potentials to be applied for the temperature control in the double skin envelope buildings.

• Korean Journal of Medicinal Crop Science
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• v.10 no.4
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• pp.237-242
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• 2002

It was found that the purified extract from A. gigas Nakai (polysaccharide, M.W., 25 kD) controled differentiating human ES cells. Its optimal supplementation concentration was decided as 0.8 $({\mu}g/ml)$ to efficiently control the differentiation. It also enhanced the cell growth, compared to the control. However, most widely used and commercially available differentiating agent, Leukemia Inhibitory Factor (LIF) negatively affected on the cell growth even though it controls the differentiation of ES cells, down to 40-50 % based on morphological observation and telomerase activity. It was presumed that the extract first affected on cell membrane and resulted in controlling signal system, then amplify gene expression of telomere, which enhanced the telomerase activity up to three times compared to the control. LIF only increased the enzyme activity up to two times. It was confirmed that the extract from A. gigas Nakai could be used for substituting currently used differentiation controlling agent, LIF from animal resources as a cheap plant resource and not affecting the cell growth. It can broaden the application of the plants not only to functional foods and their substitutes but also to fine chemicals and most cutting-edge biopharmaceutical medicine.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1594-1597
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• 2005

A rapid development and a wide use of the Internet have expanded a network environment. Further, the network environment has become more complex due to a simple and convenient network connection and various services of the Internet. However, the Internet has been constantly exposed to the danger of various network attacks such as a virus, a hacking, a system intrusion, a system manager authority acquisition, an intrusion cover-up and the like. As a result, a network security technology such as a virus vaccine, a firewall, an integrated security management, an intrusion detection system, and the like are required in order to handle the security problems of Internet. Accordingly, a router, which is a key component of the Internet, controls a data packet flow in a network and determines an optimal path thereof so as to reach an appropriate destination. An error of the router or an attack against the router can damage an entire network. This paper relates to a method for RSMS (router security management system) for secure networking based on a security policy. Security router provides functions of a packet filtering, an authentication, an access control, an intrusion analysis and an audit trail in a kernel region. Security policy has the definition of security function against a network intrusion.

• KIEAE Journal
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• v.17 no.4
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• pp.83-88
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• 2017

Purpose: The objective of this study is to develop a predictive model for calculating the amount of cooling load for the different setback temperatures during the setback period. An artificial neural network (ANN) is applied as a predictive model. The predictive model is designed to be employed in the control algorithm, in which the amount of cooling load for the different setback temperature is compared and works as a determinant for finding the most energy-efficient optimal setback temperature. Method: Three major steps were conducted for proposing the ANN-based predictive model - i) initial model development, ii) model optimization, and iii) performance evaluation. Result:The proposed model proved its prediction accuracy with the lower coefficient of variation of the root mean square errors (CVRMSEs) of the simulated results (Mi) and the predicted results (Si) under generally accepted levels. In conclusion, the ANN model presented its applicability to the thermal control algorithm for setting up the most energy-efficient setback temperature.